Recovery of sulfur from its ores



G. A. BRAGG.

RECOVERY OF SULFUR FROM ITS ORES. APPLICATION FILED MAR. 13. 1918. RENEWED SEPT. 12, I919.

1,374,422. at ted Apr- 12, 1921.

UNITED STATES PATENT oF Ic GILBERT A. BRAGG, OF THOMPSON, NEVADA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO TEXAS GULF SULPHUR COMFANY, OF BAY CITY, TEXAS, A CORPORATION OF TEXAS.

RECOVERY OF SULFUR FROM ITS ORES.

Application filed. March 13, 1918, Serial No. 222,223. Renewed-September 12, 1919. Serial No. 323,438.

To all whom it may concern:

Be it known that I, GILBERT A. BRAGG, a citizen of the United States, residing at Thompson, in the county of Lyon, State of Nevada, have invented certain new and useful Improvements in the Recovery of Sulfur from Its Ores; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to the recovery of sulfurfrom its ores, wherein the sulfur, in a native or elemental state, is associated with silica and other gangue material.

The main characteristic feature of the invention consists in heating the ore, in a suitable state of. subdivision, to the melting point of sulfur, in an appropriate liquid medium, thereby melting the individual sulfur particles contained in the ore pulp, and then causing a coalescence" of the individual melted particles of sulfur, followed by solidification into grains or granules of a larger size than the particles of gangue,

whereby the subsequent separation of the sulfur from the gangue is readily "efiected.

In the preferred practice of the invention, the sulfur ore is firstcrushed, ground, or otherwise comminuted to a suitable conditionlof subdivision, say 40 mesh. The

- finely" ground ore is then mixed with a suitable liquid medium of such a character that it may be raised to a temperature above the melting point of the sulfur contained in the ore. For this purpose, water may be employed, mixed with the finely-divided sulfur ore to form an ore pulp. It will be found suitable, in most cases, to employ equal weights of water and ore in making up the pulp, although it Wlll be understood that the ratio of the one to the other may be varied, as circumstances may require.

The ore pulp mixture is then admitted into a suitable container and its temperature is raised, preferably by the injection of live steam. The container is closed so that the steam, admitted at an appropriate temperature and pressure will raise the pressure and temperature of water in the container to such a degree that the individual particles of sulfur will melt. Steam into the ore pulp tends to agitate the The injection of the mass but, in addition to such agitation, the container. itself is preferably rotated. The molten sulfur, under the influence of the agitation, tends to agglomerate in lumps or granules much larger than the particles of than thegangue, is retained in a commencially pure state by the screen, while the gangue material passes through the screen.

and is run to waste or treated for such other values as it may contain. tained by the screen may be dried, melted, and cast into any desirable shape.

Patented Ap1-.12,1 9 21. I

A cylindrical steel container is preferably employed in the, practice of the invention,

and, as hereinbefore indicated, the mixture of ore, crushed to pass a screen of 40 mesh,

is mixed with an equal Weight of'water, and is heated to the melting point of the sulfur contained in the. ore, 40 pounds of steam pressure being usually ample for the purpose. The container is arranged for rotation around its own axis, which is inclined at an angle of say 15 to the horizontal, and is suitably equipped for charging and discharging the ore, and for the admission of the steam,preferably at the lower end of the container. The container is revolved slowly (-say at 5 or 6 revolutions per minute which tends to bring the particles of 'sul ur together and to effect their agglomeration intothe larger lumps or granules desired. In most cases, it will be found advantageous to fill. the container to within a short distance from the top.

'It is desirable to rotate the container slowly, as indicated, so that the lumps of sulfur in passing down the incline may not be subjected to any material grinding action by the ganguefwhich would otherwise tend to disintegratethem.

At the termination ofthe operation, the

mixture of gangue and sulfur is discharged 75 The sulfur rea into an inclined trommel, partially submerged in water, and carrying a 40 mesh tion. In the drawing, the rotatable cylin-- drical steel container 5 for heating'the mixture of finely divided ore and Water is represented as having a charging man-hole 6 at its higher end and a discharge man-hole 7 at its lower end.. A feed chute 8 may be provided for conducting the finely divided ore, or a mixture ofore and Water, to the charging man-hole 6. Steam is admitted to'the container 5 by means of a steam pipe 9 having a pressure gage '10. The mixture of gangue and agglomerated lumps or granules of I solid sulfur are discharged rom the man-hole 7, through a chute 11,

- into the upper end of an inclined rotating .'d1vided .ore in a suitable li uid ;medium, to"

"from the trommel 12. The trommel is partially submerged by the "water contained in a tank 13. The gangue asses through the interstices of the cylin ric'al screen of the trommel into a hopper 14 and is discharged throu h a pipe 15 having a valve 16. The resoli ified lumps or granules of sulfur are too .large to pass through the interstices of the screen and are accordingly discharged from the lower end of the rotating trommel,-

through a pipe 17 having a valve 18, on to aninclined screen 19, where the recovered sulfur is separated from the water.

Having thus described my invention what I claim is:

1. The method of recovering sulfur from its ores, which comprises heating an ore pulp, made up of a mixture of the finely the melting point of the sul r contained in the ore pulp, agitating the mass so as to cause coalescence of individual 'melted sulfur particles into aggregates larger than the gangue particles, solidifying the sulfur ag-' gregates thus formed, and ultimately separating. the solidified sulfur aggregates gangue; substantially -as' described. ,v

2. The method of recovering sulfur from its ores, which comprises char ing an orc pulp made up of a mixture 0 the finely divided ore in a suitable liquid medium into an inclined container, heating the charge so as to melt the sulfur contained in the ore, and rotating the container, so as to cause coalescence of individual melted sulfur particles into aggregates larger than the gangue particles, solidifying the sulfur aggregates thus formed and .ultimately separating the solidified sulfur aggregates from the angue; substantially as described.

3. he method of recovering sulfur from its ores, which comprises heating an ore.

pulp, made up of a mixture of the finelydivided ore in water, at a temperature sufficient to melt the sulfur contained in the ore pulp, agitating the mass so as to cause coalescence of individual melted sulfur particles into'aggre'gates larger than the gangue particles, solidifying the sulfur aggregates thus formed and ultimately separating the solidified sulfur aggregates from the gangue; substantially as described.

4:. The method of recovering sulfur from its ores,which comprises charging an ore pulp, made up of a mixture of the finelydivided ore in water, into an inclined container, heating the pul at a temperature suflicient to melt the'sul ur contained therein, rotating the inclined container at a rate sufficient to cause individual melted sulfur particles to coalesce into aggregates larger than the gangue particles, solidifying the sulfur aggregates thus formed and ultimately separating the solidified sulfur aggregates from the gangue; substantially as described.

5. The method of recovering sulfur from its ores, which comprises heating a sulfurcontaining ore to the meltin point of sulfur in the presence of a liquid medium and thereby meltin the sulfur therein, causing the thus me ted sulfur to solidify into aggregates of a larger size than the particles of gangue associated with. the

solidified aggregates of sulfur, and separating the solidified sulfur aggregates from the particles of gangue assoclated therewith; substantially as described.

6. The method of recogvering sulfur from its ores, which comprises heating a sulfurcontaining ore to the melting point of sulfur and thereby melting the sulfur therein under such conditions that the gangue particlesare wetted and coalescence of the melted sulfur thereby promoted, causing the thus melted sulfur to solidify into aggregates of a larger size than the particles of gangue associated with the solidified aggre gates of sulfur, and separating the solidified sulfur aggregates from the particles of gangue associated therewith; substantially as described. 4

In testimony whereof I afiix my signature.

s G LBERT A. BRAGG. 

